I) Melting point: Organic compounds generally have lower melting points (often below 300 °C) due to weaker intermolecular forces, while inorganic compounds generally have higher* melting po

b)

• i) Melting point: Organic compounds generally have lower melting points (often below 300 °C) due to weaker intermolecular forces, while inorganic compounds generally have higher melting points due to strong ionic or covalent bonds.
• ii) Boiling point: Organic compounds generally have lower boiling points, while inorganic compounds generally have higher boiling points.
• iii) Solubility in water: Organic compounds are often insoluble or sparingly soluble in water (unless they are polar), while many inorganic compounds are soluble in water.
• iv) Conductivity: Organic compounds are generally poor conductors of electricity (non-electrolytes), while inorganic compounds (especially ionic ones) are often good conductors when molten or dissolved in water.
• v) Biodegradability: Many organic compounds are biodegradable (broken down by living organisms), while inorganic compounds are generally not biodegradable.

c)

i) Gestation period: This is the length of time from conception to birth in a pregnant ruminant.

ii) Heat period (Estrus): This is the period when a female ruminant is sexually receptive and willing to mate, often accompanied by physiological and behavioral changes.

iii) Parturition: This refers to the act of giving birth in ruminants, marking the end of the gestation period.

d)

i) A recessive trait is a characteristic that is only expressed when an individual inherits two copies of the recessive allele (one from each parent), meaning the individual is homozygous recessive for that trait.

ii) The genotypes are: * α) A sickle cell carrier: $\boxed{Hb^A Hb^S}$ * β) A person with Blood Group B: $\boxed{I^B I^B}$ or $\boxed{I^B i}$

4. (a)

i) The groups to which the compounds belong are: * W: Alkanol (or alcohol) * X: Alkanoic acid (or carboxylic acid) * Z: Alkanoate (or ester)

ii) One acid that can be represented by Y is sulfuric acid ($\text{H}_2\text{SO}_4$).

iii) The function of Y (the acid) in this reaction is to act as a catalyst to speed up the reaction and as a dehydrating agent to remove water, shifting the equilibrium towards product formation.

b) Five causes of mortality during brooding of day-old chicks are:

• Starvation or dehydration (failure to find food or water)
• Temperature stress (brooder too cold or too hot)
• Diseases (e.g., bacterial or viral infections)
• Predation
• Physical injury (e.g., trampling by other chicks)

c)

i) Decomposers are organisms that break down dead organic matter, such as dead plants and animals, and waste products, returning essential nutrients to the soil and atmosphere for reuse by producers.

ii) Four examples of decomposers in a forest ecosystem are: * Bacteria * Fungi (e.g., mushrooms, molds) * Earthworms * Insects (e.g., dung beetles, maggots)

d) The function of each of the following parts of the mammalian ear:

i) Pinna: The visible outer part of the ear that collects and funnels sound waves into the ear canal.

ii) Cochlea: A spiral-shaped, fluid-filled structure in the inner ear that converts sound vibrations into electrical nerve impulses that are sent to the brain.

iii) Eustachian tube: A tube connecting the middle ear to the nasopharynx, which equalizes air pressure between the middle ear and the outside atmosphere.

iv) Semi-circular canal: Three fluid-filled loops in the inner ear that detect rotational movements of the head and are crucial for maintaining balance.

5. (a)

i) Demagnetization is the process of removing or significantly reducing the magnetic properties of a magnetic material, causing it to lose its ability to attract or repel other magnetic materials.

ii) Three ways by which a magnet could be demagnetized are: * Heating it above its Curie temperature. * Hammering or dropping it repeatedly (mechanical shock). * Placing it in an alternating current (AC) solenoid and slowly withdrawing it.

b)

i) A hazardous substance is any substance that can cause harm to humans, animals, or the environment due to its chemical, physical, or toxicological properties.

ii) Name one: * α) Corrosive household substance: Drain cleaner (e.g., containing sodium hydroxide) * β) Flammable laboratory substance: Ethanol * γ) Toxic laboratory substance: Mercury compounds

c)

i) Hand mating: This is a controlled breeding system where a specific male is intentionally brought to a specific female for mating, often under direct human supervision. This allows for precise genetic selection and record-keeping.

ii) Pasture mating: This is an uncontrolled breeding system where males and females are allowed to cohabitate in a pasture or herd, and mating occurs naturally without direct human intervention or selection of specific pairs.